The purpose of the study is to determine the effects of breakfast cereals with varying amounts of soluble and insoluble fiber combined with complex and simple carbohydrate on the metabolic response to long-term moderate intensity exercise. The influence of pre-exercise feedings of these cereals on exercise time to exhaustion will also be determined. We hypothesize that a breakfast cereal with a high soluble fiber content will produce a lower glycemic response than a breakfast cereal with little or no soluble fiber; and that this lower glycemic response will provide longer lasting glucose availability during submaximal exercise. A more sustained glucose availability will decrease the rate of muscle glycogen utilization, spare liver glycogen and enhance performance.